Detailed hardware description
Issue D
45
Floppy port
The GEMINI provides a slim type floppy port, supporting up to two floppy drives.
GPIO interface
The GEMINI includes a programmable 8-bit digital I/O interface. This provides general
purpose I/O’s to the user’s application. The eight bidirectional lines are open collector
and 5V compatible. GP0/1/6/7 have weak internal pull-ups.
Watchdog
The GEMINI supports a watchdog timer, integrated in the super IO chip with a software
selectable timeout of 1ms to 255s. This can be used to generate a complete hardware
system reset when an error causes a system lockup. By default, the watchdog timer is
disabled and once enabled must be triggered within the timeout period programmed.
IrDA
An infrared port is available which supports the following infrared standards:
•
Infrared Data Association (IrDA) V1.0 SIR with baud rates up to 115.2kbps.
•
SHARP ASK-IR protocol with baud rates up to 57.6kbps.
Enabling the infrared port prevents operation of Serial Port COM2. The infrared
port should be disconnected before using the COM2 port.
Parallel port
The GEMINI provides a parallel port that can be used to connect an external printer, tape
drive, disk drive, scanner etc., or can provide additional digital I/O capability.
The port is both IBM XT/AT and IEEE1284 compatible. It supports Standard Parallel Port
(SPP), Enhanced Parallel Port (EPP) and Extended Capabilities Port (ECP) modes.
Hardware monitor
The SIO has an integrated HW monitor that provides a combination of voltage and
thermal monitoring. It also provides support for PWM fan speed control and monitoring.
The HWM monitors the CPU core, VBAT, +3.3V, +5V, +5V standby and +12V supply
rails. CPU and ambient temperature thermal diodes are also monitored.
Keyboard and mouse controller
The SIO contains a universal keyboard controller based on 8042 compatible instruction
set. Four signals pins are provided which allow for the connection of two external PS/2
devices such as a keyboard and mouse.
